Compound and organic photoelectronic device and image sensor

ABSTRACT

A compound may be represented by Chemical Formula 1, an organic photoelectronic device may include a first electrode and a second electrode facing each other with an active layer that includes the compound represented by Chemical Formula 1 between the first electrode and the second electrode, and an image sensor may include the organic photoelectronic device.

CROSS REFERENCE TO RELATED APPLICATION

This application claims priority to and the benefit of Korean PatentApplication No. 10-2014-0046266 filed in the Korean IntellectualProperty Office on Apr. 17, 2014, the entire contents of which areincorporated herein by reference.

BACKGROUND 1. Field

Example embodiments relate to a compound, an organic photoelectronicdevice, and an image sensor including the same.

2. Description of the Related Art

A photoelectronic device converts light into an electrical signal usingphotoelectronic effects. The photoelectronic device may include aphotodiode and a phototransistor, and may be applied to an image sensor.

An image sensor including a photodiode requires relatively highresolution and thus a relatively small pixel. At present, a siliconphotodiode is widely used, but has a problem of deteriorated sensitivitybecause the silicon photodiode has a relatively small absorption areadue to relatively small pixels. Accordingly, an organic material that iscapable of replacing silicon has been researched.

The organic material has a relatively high extinction coefficient andselectively absorbs light in a particular wavelength region depending ona molecular structure, and thus may simultaneously replace a photodiodeand a color filter and resultantly improve sensitivity and contribute torelatively high integration.

SUMMARY

Example embodiments provide a compound being selectively capable ofabsorbing light in a green wavelength region.

Example embodiments also provide an organic photoelectronic device thatselectively absorbs light in a green wavelength region and improvesefficiency.

Example embodiments also provide an image sensor including the organicphotoelectronic device.

According to example embodiments, a compound may be represented by thefollowing Chemical Formula 1.

In the above Chemical Formula 1,

R¹ is one of a substituted or unsubstituted C₁ to C₃₀ alkyl group, asubstituted or unsubstituted C₃ to C₃₀ cycloalkyl group, a substitutedor unsubstituted C₂ to C₃₀ heterocycloalkyl group, a substituted orunsubstituted C₆ to C₃₀ aryl group, a substituted or unsubstituted C₃ toC₃₀ heteroaryl group, a substituted or unsubstituted C₆ to C₃₀ arylaminegroup, an amine group, a halogen, a hydroxy group, a cyano group, acyanovinyl group, a dicyanovinyl group, and a combination thereof,

each of R² to R⁷ are independently present or two adjacent groups of R²to R⁷ are linked to each other to form a fused ring, and are one ofhydrogen, a substituted or unsubstituted C₁ to C₃₀ alkyl group, asubstituted or unsubstituted C₃ to C₃₀ cycloalkyl group, a substitutedor unsubstituted C₂ to C₃₀ heterocycloalkyl group, a substituted orunsubstituted C₆ to C₃₀ aryl group, a substituted or unsubstituted C₃ toC₃₀ heteroaryl group, a substituted or unsubstituted C₁ to C₃₀ carbonylgroup, a substituted or unsubstituted C₆ to C₃₀ arylamine group, anamine group, a halogen, a hydroxy group, a cyano group, a cyanovinylgroup, a dicyanovinyl group, and a combination thereof, and

each of X¹ and X² are independently one of a halogen, ahalogen-containing group, and a combination thereof.

The compound may have a maximum absorption wavelength (λ_(max)) of about500 nm to about 600 nm.

The compound may have a HOMO level of about 4.3 to about 7.0 eV and anenergy bandgap of about 1.9 to about 3.1 eV.

In the above Chemical Formula 1, each of X¹ and X² may independently befluorine, and R¹ may independently be one of a substituted orunsubstituted C₆ to C₃₀ aryl group, a cyano group, and a combinationthereof.

The compound may be a compound represented by one of the followingChemical Formulae 1a to 1n.

According to example embodiments, a thin film may include the compoundof example embodiments.

The thin film may show an absorbance curve having full width at halfmaximum (FWHM) of about 50 nm to about 150 nm.

According to example embodiments, an organic photoelectronic device mayinclude a first electrode and a second electrode facing each other, andan active layer between the first electrode and the second electrode,the active layer including a compound represented by the followingChemical Formula 1.

In the above Chemical Formula 1,

R¹ is one of a substituted or unsubstituted C₁ to C₃₀ alkyl group, asubstituted or unsubstituted C₃ to C₃₀ cycloalkyl group, a substitutedor unsubstituted C₂ to C₃₀ heterocycloalkyl group, a substituted orunsubstituted C₆ to C₃₀ aryl group, a substituted or unsubstituted C₃ toC₃₀ heteroaryl group, a substituted or unsubstituted C₁ to C₃₀ acylgroup, a substituted or unsubstituted C₆ to C₃₀ arylamine group, anamine group, a halogen, a hydroxy group, a cyano group, a cyanovinylgroup, a dicyanovinyl group, and a combination thereof,

each of R² to R⁷ are independently present or two adjacent groups of R²to R⁷ are linked to each other to form a fused ring, and are one ofhydrogen, a substituted or unsubstituted C₁ to C₃₀ alkyl group, asubstituted or unsubstituted C₁ to C₃₀ alkenyl group, a substituted orunsubstituted C₃ to C₃₀ cycloalkyl group, a substituted or unsubstitutedC₃ to C₃₀ cycloalkenyl group, a substituted or unsubstituted C₂ to C₃₀heterocycloalkyl group, a substituted or unsubstituted C₃ to C₃₀heterocycloalkenyl group, a substituted or unsubstituted C₆ to C₃₀ arylgroup, a substituted or unsubstituted C₃ to C₃₀ heteroaryl group, asubstituted or unsubstituted C₁ to C₃₀ acyl group, a substituted orunsubstituted C₁ to C₃₀ carbonyl group, a substituted or unsubstitutedC₆ to C₃₀ arylamine group, an amine group, a halogen, a hydroxy group, acyano group, a cyanovinyl group, a dicyanovinyl group, and a combinationthereof, and

each of X¹ and X² are independently one of a halogen, ahalogen-containing group, and a combination thereof.

The compound may have a maximum absorption wavelength (λ_(max)) of about500 nm to about 600 nm.

The active layer may show an absorbance curve having a full width athalf maximum (FWHM) of about 50 nm to about 150 nm.

The compound may have a HOMO level of about 4.3 to about 7.0 eV and anenergy bandgap of about 1.9 to about 3.1 eV.

In the above Chemical Formula 1, each of X¹ and X² may independently befluorine, and R¹ may be one of a substituted or unsubstituted C₆ to C₃₀aryl group, a cyano group, and a combination thereof.

The compound represented by the above Chemical Formula 1 may berepresented by one of the following Chemical Formulae 1a to 1p.

The active layer may further include one of a p-type semiconductorcompound and an n-type semiconductor compound.

The p-type semiconductor compound may include at least one of a compoundrepresented by the following Chemical Formula 2 and a compoundrepresented by the following Chemical Formula 3.

In the above Chemical Formula 2,

each of R⁸ to R¹⁹ are independently one of hydrogen, a substituted orunsubstituted C₁ to C₃₀ alkyl group, a substituted or unsubstituted C₃to C₃₀ cycloalkyl group, a substituted or unsubstituted C₂ to C₃₀heterocycloalkyl group, a substituted or unsubstituted C₆ to C₃₀ arylgroup, a substituted or unsubstituted C₃ to C₃₀ heteroaryl group, asubstituted or unsubstituted C₁ to C₃₀ alkoxy group, a halogen, and acombination thereof,

In the above Chemical Formula 3,

each of R²⁰ to R³¹ are independently one of hydrogen, a substituted orunsubstituted C₁ to C₃₀ alkyl group, a substituted or unsubstituted C₆to C₃₀ aryl group, a substituted or unsubstituted C₃ to C₃₀ heteroarylgroup, a halogen, a halogen-containing group, and a combination thereof,and

X is an anion.

The active layer may selectively absorb light in a green wavelengthregion.

The active layer may include an intrinsic layer having a first side anda second side including the compound represented by the above ChemicalFormula 1.

The active layer may further include at least one of a p-type layer onthe first side of the intrinsic layer and an n-type layer on the secondside of the intrinsic layer.

According to example embodiments, an image sensor may include theorganic photoelectronic device.

The image sensor may include a semiconductor substrate integrated with aplurality of first photo-sensing devices sensing light in a bluewavelength region and a plurality of second photo-sensing devicessensing light in a red wavelength region, a color filter layer on thesemiconductor substrate and including a blue filter that selectivelyabsorbs light in the blue wavelength region and a red filter thatselectively absorbs light in the red wavelength region, and the organicphotoelectronic device on the color filter layer and selectivelyabsorbing light in a green wavelength region.

BRIEF DESCRIPTION OF THE DRAWINGS

These and/or other aspects will become apparent and more readilyappreciated from the following description of the embodiments, taken inconjunction with the accompanying drawings in which:

FIG. 1 is a cross-sectional view showing an organic photoelectronicdevice according to example embodiments,

FIG. 2 is a cross-sectional view showing an organic photoelectronicdevice according to example embodiments,

FIG. 3 is a cross-sectional view showing a CMOS image sensor accordingto example embodiments,

FIG. 4 is a cross-sectional view showing a CMOS image sensor accordingto example embodiments,

FIG. 5 is a photograph showing thin film characteristics of a compoundaccording to Synthesis Example 3,

FIG. 6 to FIG. 11 are graphs respectively showing external quantumefficiency (EQE) of each organic photoelectronic device according toExamples 1 to 6 depending on a wavelength and a voltage,

FIG. 12 is a graph showing current density change of the organicphotoelectronic device according to Example 4 when allowed to stand at120° C. for 30 minutes, and

FIG. 13 is a graph showing current density change of the organicphotoelectronic device according to Example 5 when allowed to stand at120° C. for 30 minutes.

DETAILED DESCRIPTION

Example embodiments will hereinafter be described in detail, and may beeasily performed by those who have common knowledge in the related art.However, this disclosure may be embodied in many different forms and isnot construed as limited to the example embodiments set forth herein.

As used herein, when a definition is not otherwise provided, the term“substituted” refers to one substituted with a substituent selected froma halogen (F, Br, Cl, or I), a hydroxy group, an alkoxy group, a nitrogroup, a cyano group, an amino group, an azido group, an amidino group,a hydrazino group, a hydrazono group, a carbonyl group, a carbamylgroup, a thiol group, an ester group, a carboxyl group or a saltthereof, a sulfonic acid group or a salt thereof, phosphoric acid or asalt thereof, a C₁ to C₂₀ alkyl group, a C₂ to C₂₀ alkenyl group, a C₂to C₂₀ alkynyl group, a C₆ to C₃₀ aryl group, a C₇ to C₃₀ arylalkylgroup, a C₁ to C₄ alkoxy group, a C₁ to C₂₀ heteroalkyl group, a C₃ toC₂₀ heteroarylalkyl group, a C₃ to C₃₀ cycloalkyl group, a C₃ to C₁₅cycloalkenyl group, a C₆ to C₁₅ cycloalkynyl group, a C₂ to C₂₀heterocycloalkyl group, and a combination thereof, instead of hydrogenof a compound.

As used herein, when specific definition is not otherwise provided, theterm “hetero” refers to one including 1 to 3 heteroatoms selected fromN, O, S, and P.

In the drawings, the thickness of layers, films, panels, regions, etc.,are exaggerated for clarity. Like reference numerals designate likeelements throughout the specification. It will be understood that whenan element such as a layer, film, region, or substrate is referred to asbeing “on” another element, it can be directly on the other element orintervening elements may also be present. In contrast, when an elementis referred to as being “directly on” another element, there are nointervening elements present.

In the drawings, parts having no relationship with the description areomitted for clarity of the embodiments, and the same or similarconstituent elements are indicated by the same reference numeralthroughout the specification.

It should be understood that, although the terms first, second, third,etc. may be used herein to describe various elements, components,regions, layers and/or sections, these elements, components, regions,layers, and/or sections should not be limited by these terms. Theseterms are only used to distinguish one element, component, region,layer, or section from another region, layer, or section. Thus, a firstelement, component, region, layer, or section discussed below could betermed a second element, component, region, layer, or section withoutdeparting from the teachings of example embodiments.

Spatially relative terms (e.g., “beneath,” “below,” “lower,” “above,”“upper,” and the like) may be used herein for ease of description todescribe one element or feature's relationship to another element(s) orfeature(s) as illustrated in the figures. It should be understood thatthe spatially relative terms are intended to encompass differentorientations of the device in use or operation in addition to theorientation depicted in the figures. For example, if the device in thefigures is turned over, elements described as “below” or “beneath” otherelements or features would then be oriented “above” the other elementsor features. Thus, the term “below” may encompass both an orientation ofabove and below. The device may be otherwise oriented (rotated 90degrees or at other orientations) and the spatially relative descriptorsused herein interpreted accordingly.

The terminology used herein is for the purpose of describing variousembodiments only and is not intended to be limiting of exampleembodiments. As used herein, the singular forms “a,” “an,” and “the” areintended to include the plural forms as well, unless the context clearlyindicates otherwise. It will be further understood that the terms“includes,” “including,” “comprises,” and/or “comprising,” when used inthis specification, specify the presence of stated features, integers,steps, operations, elements, and/or components, but do not preclude thepresence or addition of one or more other features, integers, steps,operations, elements, components, and/or groups thereof.

Example embodiments are described herein with reference tocross-sectional illustrations that are schematic illustrations ofidealized embodiments (and intermediate structures) of exampleembodiments. As such, variations from the shapes of the illustrations asa result, for example, of manufacturing techniques and/or tolerances,are to be expected. Thus, example embodiments should not be construed aslimited to the shapes of regions illustrated herein but are to includedeviations in shapes that result, for example, from manufacturing.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which example embodiments belong. Itwill be further understood that terms, including those defined incommonly used dictionaries, should be interpreted as having a meaningthat is consistent with their meaning in the context of the relevant artand will not be interpreted in an idealized or overly formal senseunless expressly so defined herein.

Hereinafter, a compound according to example embodiments is described.

A compound according to example embodiments is represented by thefollowing Chemical Formula 1.

In the above Chemical Formula 1,

R¹ is one of a substituted or unsubstituted C₁ to C₃₀ alkyl group, asubstituted or unsubstituted C₃ to C₃₀ cycloalkyl group, a substitutedor unsubstituted C₂ to C₃₀ heterocycloalkyl group, a substituted orunsubstituted C₆ to C₃₀ aryl group, a substituted or unsubstituted C₃ toC₃₀ heteroaryl group, a substituted or unsubstituted C₆ to C₃₀ arylaminegroup, an amine group, a halogen, a hydroxy group, a cyano group, acyanovinyl group, a dicyanovinyl group, and a combination thereof,

each of R² to R⁷ are independently present or two adjacent groups of R²to R⁷ are linked to each other to form a fused ring, and are one ofhydrogen, a substituted or unsubstituted C₁ to C₃₀ alkyl group, asubstituted or unsubstituted C₃ to C₃₀ cycloalkyl group, a substitutedor unsubstituted C₂ to C₃₀ heterocycloalkyl group, a substituted orunsubstituted C₆ to C₃₀ aryl group, a substituted or unsubstituted C₃ toC₃₀ heteroaryl group, a substituted or unsubstituted C₁ to C₃₀ carbonylgroup, a substituted or unsubstituted C₆ to C₃₀ arylamine group, anamine group, a halogen, a hydroxy group, a cyano group, a cyanovinylgroup, a dicyanovinyl group, and a combination thereof, and

each of X¹ and X² are independently one of a halogen, ahalogen-containing group, and a combination thereof.

The compound may selectively absorb light in a green wavelength region,and may have a maximum absorption wavelength (λ_(max)) of about 500 nmto about 600 nm.

The compound may show an absorbance curve having a relatively narrowfull width at half maximum (FWHM) of about 50 nm to about 150 nm in athin film state. Herein, the FWHM is a width of a wavelengthcorresponding to a half of a maximum absorbance point, and a smallerFWHM indicates selective absorbance of light in a relatively narrowwavelength region and a relatively high wavelength selectivity.Accordingly, a compound having FWHM within the range may have relativelyhigh selectivity for a green wavelength region.

The compound may have a HOMO level of about 4.3 to about 7.0 eV and anenergy bandgap of about 1.9 to about 3.1 eV. When the compound has theHOMO level and energy bandgap within the ranges, the compound may beapplied as an n-type or p-type semiconductor that selectively absorbslight in a green wavelength region, and thus has relatively highexternal quantum efficiency (EQE) thereby improving photoelectricconversion efficiency.

For example, in the above Chemical Formula 1, X¹ and X² mayindependently be fluorine.

For example, in the above Chemical Formula 1, R¹ may be one of asubstituted or unsubstituted C₆ to C₃₀ aryl group, a cyano group, and acombination thereof. The aryl group may be, for example, a phenyl group.

The compound represented by the above Chemical Formula 1 may berepresented by one of the following Chemical Formulae 1a to 1n, but isnot limited thereto.

Hereinafter, an organic photoelectronic device including the compoundaccording to example embodiments is described referring to the drawing.

FIG. 1 is a cross-sectional view showing an organic photoelectronicdevice according to example embodiments.

Referring to FIG. 1, an organic photoelectronic device 100 according toexample embodiments includes a first electrode 10 and a second electrode20 facing each other, and an active layer 30 interposed between thefirst electrode 10 and the second electrode 20.

One of the first electrode 10 and the second electrode 20 is an anodeand the other is cathode. At least one of the first electrode 10 and thesecond electrode 20 may be a light-transmitting electrode, and thelight-transmitting electrode may be made of, for example, a transparentconductor such as indium tin oxide (ITO) or indium zinc oxide (IZO), ora metal thin layer of a thin monolayer or a multilayer. When one of thefirst electrode 10 and the second electrode 20 is anon-light-transmitting electrode, it may be made of, for example, anopaque conductor such as aluminum (Al).

The active layer 30 includes a p-type semiconductor material and ann-type semiconductor material to form a pn junction, and absorbs lightexternally to generate excitons and then separates the generatedexcitons into holes and electrons.

The active layer 30 includes a compound represented by the followingChemical Formula 1.

In the above Chemical Formula 1,

R¹ is one of a substituted or unsubstituted C1 to C₃₀ alkyl group, asubstituted or unsubstituted C3 to C₃₀ cycloalkyl group, a substitutedor unsubstituted C2 to C₃₀ heterocycloalkyl group, a substituted orunsubstituted C6 to C₃₀ aryl group, a substituted or unsubstituted C3 toC₃₀ heteroaryl group, a substituted or unsubstituted C1 to C₃₀ acylgroup, a substituted or unsubstituted C6 to C₃₀ arylamine group, anamine group, a halogen, a hydroxy group, a cyano group, a cyanovinylgroup, a dicyanovinyl group, and a combination thereof,

each of R² to R⁷ are independently present or two adjacent groups of R²to R⁷ are linked to each other to form a fused ring, and are one ofhydrogen, a substituted or unsubstituted C1 to C₃₀ alkyl group, asubstituted or unsubstituted C1 to C₃₀ alkenyl group, a substituted orunsubstituted C3 to C₃₀ cycloalkyl group, a substituted or unsubstitutedC3 to C₃₀ cycloalkenyl group, a substituted or unsubstituted C2 to C₃₀heterocycloalkyl group, a substituted or unsubstituted C3 to C₃₀heterocycloalkenyl group, a substituted or unsubstituted C6 to C₃₀ arylgroup, a substituted or unsubstituted C3 to C₃₀ heteroaryl group, asubstituted or unsubstituted C1 to C₃₀ acyl group, a substituted orunsubstituted C1 to C₃₀ carbonyl group, a substituted or unsubstitutedC6 to C₃₀ arylamine group, an amine group, a halogen, a hydroxy group, acyano group, a cyanovinyl group, a dicyanovinyl group, and a combinationthereof, and

each of X¹ and X² are independently one of a halogen, ahalogen-containing group, and a combination thereof.

The compound may selectively absorb light in a green wavelength region,and the active layer 30 including the compound may selectively absorblight in a green wavelength having a maximum absorption wavelength(λ_(max)) of about 500 nm to about 600 nm.

The active layer 30 may show a relatively narrow absorbance curve havinga full width at half maximum (FWHM) of about 50 nm to about 150 nm.Accordingly, the active layer 30 may have relatively high selectivityfor light in a green wavelength region.

The compound may have a HOMO level of about 4.3 to about 7.0 eV and anenergy bandgap of about 1.9 to about 3.1 eV. When the compound has theHOMO level and the energy bandgap within the ranges, the compound may beapplied as an n-type or p-type semiconductor to effectively absorb lightin a green wavelength region.

For example, in the above Chemical Formula 1, X¹ and X² mayindependently be fluorine.

For example, in the above Chemical Formula 1, R¹ may be one of asubstituted or unsubstituted C₆ to C₃₀ aryl group, a cyano group, and acombination thereof. The aryl group may be, for example, a phenyl group.

The compound may be, for example, represented by the following ChemicalFormulae 1a to 1p, but is not limited thereto.

The compound may be applied as an n-type semiconductor or a p-typesemiconductor in the active layer 30. When the compound is applied as ann-type semiconductor, a p-type semiconductor may be further included toform a pn junction with the n-type semiconductor, while when thecompound is applied as a p-type semiconductor, an n-type semiconductormay be further included to form a pn junction with the p-typesemiconductor.

For example, when the compound is an n-type semiconductor, a p-typesemiconductor represented by the following Chemical Formula 2 may befurther included.

In the above Chemical Formula 2,

each of R⁸ to R¹⁹ are independently one of hydrogen, a substituted orunsubstituted C₁ to C₃₀ alkyl group, a substituted or unsubstituted C₃to C₃₀ cycloalkyl group, a substituted or unsubstituted C₂ to C₃₀heterocycloalkyl group, a substituted or unsubstituted C₆ to C₃₀ arylgroup, a substituted or unsubstituted C₃ to C₃₀ heteroaryl group, asubstituted or unsubstituted C₁ to C₃₀ alkoxy group, a halogen, and acombination thereof.

The compound represented by the above Chemical Formula 2 may be, forexample, at least one of compounds represented by the following ChemicalFormulae 2a to 2h, but is not limited thereto.

For example, when the compound is an n-type semiconductor, a p-typesemiconductor represented by the following Chemical Formula 3 may befurther included.

In the above Chemical Formula 3,

each of R²⁰ to R³¹ are independently one of hydrogen, a substituted orunsubstituted C₁ to C₃₀ alkyl group, a substituted or unsubstituted C₆to C₃₀ aryl group, a substituted or unsubstituted C₃ to C₃₀ heteroarylgroup, a halogen, a halogen-containing group, and a combination thereof,and

X is an anion.

The compound represented by the above Chemical Formula 3 may be, forexample, at least one of compounds represented by the following ChemicalFormulae 3a to 3e, but is not limited thereto.

The active layer 30 may be a monolayer or a multilayer. The active layer30 may be, for example, an intrinsic layer (I layer), a p-type layer/Ilayer, an I layer/n-type layer, a p-type layer/I layer/n-type layer, anda p-type layer/n-type layer.

The intrinsic layer (I layer) may include the p-type semiconductorcompound and the n-type semiconductor compound in a ratio of about 1:100to about 100:1. The compounds may be included in a ratio ranging fromabout 1:50 to about 50:1 within the range, specifically, about 1:10 toabout 10:1, and more specifically, about 1:about 1. When the p-type andn-type semiconductors have a composition ratio within the range, anexciton may be effectively produced, and a pn junction may beeffectively formed.

The p-type layer may include the p-type semiconductor compound, and then-type layer may include the n-type semiconductor compound.

The active layer 30 may have a thickness of about 1 nm to about 500 nm,and specifically about 5 nm to about 300 nm. When the active layer 30has a thickness within the range, the active layer may effectivelyabsorb light, effectively separate holes from electrons, and deliverthem, thereby effectively improving photoelectric conversion efficiency.

In the organic photoelectronic device 100, when light enters from thefirst electrode 10 and/or second electrode 20, and when the active layer30 adsorbs light having a predetermined or given wavelength region,excitons may be produced from inside the organic photoelectronic device100. The excitons are separated into holes and electrons at the activelayer 30, the separated holes are transported to an anode that is one ofthe first electrode 10 and second electrode 20, and the separatedelectrons are transported to the cathode that is the other of and thefirst electrode 10 and second electrode 20, so as to flow a current inthe organic photoelectronic device.

Referring to FIG. 2, an organic photoelectronic device according toexample embodiments is described.

FIG. 2 is a cross-sectional view of an organic photoelectronic deviceaccording to example embodiments.

Referring to FIG. 2, an organic photoelectronic device 200 according toexample embodiments includes a first electrode 10 and a second electrode20 facing each other, and an active layer 30 interposed between thefirst electrode 10 and the second electrode 20 like the exampleembodiment illustrated in FIG. 1.

However, the organic photoelectronic device 200 according to exampleembodiments further includes charge auxiliary layers 40 and 50 betweenthe first electrode 10 and the active layer 30, and the second electrode20 and the active layer 30, respectively, unlike the example embodimentillustrated in FIG. 1. The charge auxiliary layers 40 and 50 mayfacilitate the transfer of holes and electrons separated from the activelayer 30, so as to increase efficiency.

The charge auxiliary layers 40 and 50 may be at least one selected froma hole injection layer (HIL) for facilitating hole injection, a holetransport layer (HTL) for facilitating hole transport, an electronblocking layer (EBL) for preventing or inhibiting electron transport, anelectron injection layer (EIL) for facilitating electron injection, anelectron transport layer (ETL) for facilitating electron transport, anda hole blocking layer (HBL) for preventing or inhibiting hole transport.

The charge auxiliary layers 40 and 50 may include, for example, anorganic material, an inorganic material, or an organic/inorganicmaterial. The organic material may be an organic compound having hole orelectron characteristics, and the inorganic material may be, forexample, a metal oxide (e.g., molybdenum oxide, tungsten oxide, andnickel oxide).

The hole transport layer (HTL) may include one selected from, forexample, poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)(PEDOT:PSS), polyarylamine, poly(N-vinylcarbazole), polyaniline,polypyrrole, N,N,N′,N′-tetrakis(4-methoxyphenyl)-benzidine (TPD),4-bis[N-(1-naphthyl)-N-phenyl-amino]biphenyl (α-NPD), m-MTDATA,4,4′,4″-tris(N-carbazolyl)-triphenylamine (TCTA), and a combinationthereof, but is not limited thereto.

The electron blocking layer (EBL) may include one selected from, forexample, poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)(PEDOT:PSS), polyarylamine, poly(N-vinylcarbazole), polyaniline,polypyrrole, N,N,N′,N′-tetrakis(4-methoxyphenyl)-benzidine (TPD),4-bis[N-(1-naphthyl)-N-phenyl-amino]biphenyl (α-NPD), m-MTDATA,4,4′,4″-tris(N-carbazolyl)-triphenylamine (TCTA), and a combinationthereof, but is not limited thereto.

The electron transport layer (ETL) may include one selected from, forexample, 1,4,5,8-naphthalene-tetracarboxylic dianhydride (NTCDA),bathocuproine (BCP), LiF, Alq₃, Gaq₃, Inq₃, Znq₂, Zn(BTZ)₂, BeBq₂, and acombination thereof, but is not limited thereto.

The hole blocking layer (HBL) may include one selected from, forexample, 1,4,5,8-naphthalene-tetracarboxylic dianhydride (NTCDA),bathocuproine (BCP), LiF, Alq₃, Gaq₃, Inq₃, Znq₂, Zn(BTZ)₂, BeBq₂, and acombination thereof, but is not limited thereto.

Either one of the charge auxiliary layers 40 and 50 may be omitted.

The organic photoelectronic device may be applied to various fields, forexample a solar cell, an image sensor, a photo-detector, a photo-sensor,and an organic light emitting diode (OLED), but is not limited thereto.

Hereinafter, an example of an image sensor including the organicphotoelectronic device is described referring to drawings. As an exampleof an image sensor, an organic CMOS image sensor is described.

FIG. 3 is a cross-sectional view showing an organic CMOS image sensoraccording to example embodiments.

FIG. 3 illustrates blue, green, and red pixels that are adjacent to oneanother, but is not limited thereto.

Referring to FIG. 3, an organic CMOS image sensor 300 according toexample embodiments includes a semiconductor substrate 310 integratedwith photo-sensing devices 50B and 50R, a transmission transistor (notshown), and a charge storage 55, a lower insulation layer 60, a colorfilter 70, an upper insulation layer 80, and an organic photoelectronicdevice 100.

The semiconductor substrate 310 may be a silicon substrate, and isintegrated with the photo-sensing device 50B and 50R, the transmissiontransistor (not shown), and the charge storage 55. The photo-sensingdevice 50 may be a photodiode.

The photo-sensing devices 50B and 50R, the transmission transistor,and/or the charge storage 55 may be integrated in each pixel, and asshown in the drawing, the photo-sensing devices 50B and 50R may beincluded in a blue pixel and a red pixel and the charge storage 55 maybe included in a green pixel.

The photo-sensing devices 50B and 50R sense light, the informationsensed by the photo-sensing devices may be transferred by thetransmission transistor, the charge storage 55 is electrically connectedwith the organic photoelectronic device 100, and the information of thecharge storage 55 may be transferred by the transmission transistor.

A metal wire (not shown) and a pad (not shown) are formed on thesemiconductor substrate 310. In order to decrease signal delay, themetal wire and pad may be made of a metal having low resistivity, forexample, aluminum (Al), copper (Cu), silver (Ag), and alloys thereof,but is not limited thereto. Further, it is not limited to the structure,and the metal wire and pad may be positioned under the photo-sensingdevices 50B and 50R.

The lower insulation layer 60 is formed on the metal wire and the pad.The lower insulation layer 60 may be made of an inorganic insulatingmaterial such as a silicon oxide and/or a silicon nitride, or a lowdielectric constant (low K) material such as SiC, SiCOH, SiCO, and SiOF.The lower insulation layer 60 has a trench exposing the charge storage55. The trench may be filled with fillers.

A color filter 70 is formed on the lower insulation layer 60. The colorfilter 70 includes a blue filter 70B formed in the blue pixel and a redfilter 70R filled in the red pixel. In example embodiments, a greenfilter is not included, but a green filter may be further included.

The upper insulation layer 80 is formed on the color filter 70. Theupper insulation layer 80 may eliminate a step caused by the colorfilters 70 and smoothes the surface. The upper insulation layer 80 andlower insulation layer 60 may include a contact hole (not shown)exposing a pad, and a through-hole 85 exposing the charge storage 55 ofthe green pixel.

The organic photoelectronic device 100 is formed on the upper insulationlayer 80. The organic photoelectronic device 100 includes the firstelectrode 10, the active layer 30, and the second electrode 120 asdescribed above.

The first electrode 10 and the second electrode 20 may be transparentelectrodes, and the active layer 30 selectively absorbs light in a greenwavelength region as described above and may replace a color filter of agreen pixel.

When light enters from the second electrode 20, the light in a greenwavelength region may be mainly absorbed in the active layer 30 andphotoelectrically converted, while the light in the rest of thewavelength regions passes through first electrode 10 and may be sensedin a photo-sensing device 50B and 50R.

FIG. 4 is cross-sectional view showing an organic CMOS image sensoraccording to example embodiments.

Referring to FIG. 4, an organic CMOS image sensor 400 according toexample embodiments includes a semiconductor substrate 310 integratedwith photo-sensing devices 50B and 50R, a transmission transistor (notshown), and charge storage 55, a lower insulation layer 60, colorfilters 70B and 70R, an upper insulation layer 80, and an organicphotoelectronic device 200, like the example embodiment illustrated inFIG. 3.

However, the organic photoelectronic device 200 further includes chargeauxiliary layers 40 and 50. The charge auxiliary layers 40 and 50 arethe same as above, and one of the charge auxiliary layers 40 and 50 maybe omitted.

Hereinafter, the present disclosure is illustrated in more detail withreference to examples. However, these are examples, and the presentdisclosure is not limited thereto.

SYNTHESIS EXAMPLE Synthesis Example 1

1.1 g of 2-chloro-5-benzoyl-pyrrole and 1.5 mL of POCl₃ are dissolved in60 ml of CH₂Cl₂, and the solution is agitated at room temperature for 3hours. Subsequently, 2.00 g of 2,4-dimethyl-3-ethylpyrrole is added tothe solution, and the mixture is additionally agitated for 36 hours andthen washed and dried. The obtained material is dissolved in toluene, asmall amount of triethylamine is added thereto, and the mixture isagitated at room temperature for one hour. Subsequently, 1.8 mL ofBF₃OEt₂ is added thereto, and the mixture is reacted at 100° C. for 10hours. Subsequently, the resultant is washed and vacuum-dried. Theobtained material is dissolved in 20 ml of acetonitrile, 170 μl ofpropane-1-amine is added thereto, and a material obtained by refluxingthe mixture for 10 hours while the mixture is agitated isrecrystallized, obtaining a powder-type compound represented by theabove Chemical Formula 1 m.

MALD-TOF: 409.13 (M+), 409.21 (calculated) for C₂₃H₂₆BF₂N₃O,

¹H NMR (CDCl, Bruker 500 MHz): δ 1.06 (t, 3H), 1.54 (s, 3H), 1.83 (t,3H), 2.40 (q, 2H), 2.68 (s, 3H), 4.61 (d, 2H), 6.47 (s, 1H), 7.26-7.34(m, 2H), 7.46-7.56 (m, 3H).

Synthesis Example 2

A compound represented by the above Chemical Formula 1n is obtained bydissolving the compound of Example 1 in ethanol, adding malononitrileand ammonium acetate thereto, and recrystallizing a product obtainedfrom the mixture.

MALD-TOF: 458.03 (M+), 475.22 (calculated) for C₂₆H₂₆BF₂N₅,

¹H NMR (CDCl, Bruker 500 MHz): δ 1.06 (t, 3H), 1.54 (s, 3H), 1.83 (t,3H), 2.40 (q, 2H), 2.68 (s, 3H), 4.61 (d, 2H), 6.47 (s, 1H), 7.26-7.34(m, 2H), 7.46-7.56 (m, 3H), 8.20 (s, 1H).

Synthesis Example 3

The compound of Synthesis Example 1 is dissolved in ethanol, andpiperidine and ethylacetoacetate are added thereto. Subsequently, aproduct obtained therefrom is refluxed for 4 hours and then dried andrecrystallized, obtaining a compound represented by the above ChemicalFormula 1o.

MALD-TOF: 475.21 (M+), 475.22 (calculated) for C₂₇H₂₈BF₂N₃O₂,

¹H NMR (CDCl, Bruker 500 MHz): δ 1.06 (t, 3H), 1.54 (s, 3H), 1.83 (t,3H), 2.40 (q, 2H), 2.68 (s, 3H), 4.61 (d, 2H), 6.47 (s, 1H), 7.26-7.34(m, 2H), 7.46-7.56 (m, 3H). 8.21 (s, 1H)

Synthesis Example 4

The compound of Synthesis Example 1 is dissolved in anhydrous ethanol,and piperidine and ethylcyanoacetate are added thereto. Subsequently, aproduct obtained therefrom is refluxed for 4 hours and then dried andrecrystallized, obtaining a compound represented by the above ChemicalFormula 1p.

MALD-TOF: 458.11 (M+), 458.21 (calculated) for C₂₆H₂₅BF₂N₄O,

¹H NMR (CDCl, Bruker 500 MHz): δ 1.05 (t, 3H), 1.50 (s, 3H), 1.82 (t,3H), 2.41 (q, 2H), 2.69 (s, 3H), 4.60 (d, 2H), 6.40 (s, 1H), 7.26-7.34(m, 2H), 7.52-7.83 (m, 3H) 8.13 (s, 1H)

Synthesis Example 5

The compound of Synthesis Example 3 is dissolved in ethanol,malononitrile and ammonium acetate are added thereto, and a productobtained therefrom is recrystallized, obtaining a compound representedby the above Chemical Formula 1j.

MALD-TOF: 507.47 (M+), 506.22 (calculated) for C₂₇H₂₈BF₂N₃O₂,

¹H NMR (CDCl, Bruker 500 MHz): δ 1.05 (t, 3H), 1.50 (s, 3H), 1.82 (t,3H), 2.41 (q, 2H), 2.69 (s, 3H), 4.60 (d, 2H), 6.40 (s, 1H), 7.26-7.34(m, 2H), 7.52-7.83 (m, 3H), 7.89 (s, 1H).

Evaluation 1: Absorbance Characteristics

Absorbance characteristics of the compounds according to SynthesisExamples 1 to 5 are evaluated depending on a wavelength.

The absorbance characteristics are evaluated by thermally depositingeach compound according to Synthesis Examples 1 to 5 at a speed of 0.1to 1.0 Å/s under relatively high vacuum (<10⁻⁷ Torr) to respectivelyform 50 nm to 100 nm-thick thin films and radiating ultraviolet-visibleray (UV-Vis) to the films by using a Cary 5000 UV spectroscope (VarianInc.).

The results are provided in Table 1.

Referring to Table 1, the compounds of Synthesis Examples 1 to 5 arefound to have a maximum absorbance wavelength (λ_(max)) in a range ofabout 500 nm to 600 nm and to selectively absorb light in a greenwavelength region.

TABLE 1 Maximum absorption FWHM wavelength (λmax, nm) (nm) SynthesisExample 1 573 87 Synthesis Example 2 595 115 Synthesis Example 3 582 109Synthesis Example 4 563 107 Synthesis Example 5 577 96Evaluation 2: Thin Film Characteristics

Thin film characteristics of the compound according to Synthesis Example3 are evaluated.

Surface characteristics are evaluated by thermally depositing thecompound of Synthesis Example 3 at a speed of 0.5 to 1.0 Å/s underrelatively high vacuum (<10⁻⁷ Torr) to form a 50 to 100 nm-thick filmand using an atomic force microscope (Dimension V, Veeco Co.).

FIG. 5 is a photograph showing the thin film characteristics of thecompound according to Synthesis Example 3.

Referring to FIG. 5, the thin film formed of the compound according toSynthesis Example 3 is found to have a uniform surface and improved thinfilm characteristics.

Evaluation 3: Energy Level

Energy level of the compounds represented by the following ChemicalFormulas 1a to 1p is evaluated.

The energy level is calculated as a B3LYP/6-31G basis set in a densityfunctional theory (DFT) method by using Gaussian software and evaluatedwith an AC-2 photoelectron spectrometer (Hitachi Co.).

The results are provided in Table 2.

TABLE 2 HOMO (eV) LUMO (eV) Bandgap (Eg., eV) Chemical Formula 1a −5.881−2.799 3.082 Chemical Formula 1b −5.343 −2.702 2.641 Chemical Formula 1c−5.218 −2.703 2.515 Chemical Formula 1d −4.404 −1.921 2.483 ChemicalFormula 1e −5.232 −2.292 2.94 Chemical Formula 1f −5.677 −3.279 2.398Chemical Formula 1g −4.828 −2.780 2.048 Chemical Formula 1h −6.850−4.119 2.731 Chemical Formula 1i −6.282 −3.300 2.982 Chemical Formula 1j−5.646 −3.489 2.157 Chemical Formula 1k −5.597 −3.042 2.555 ChemicalFormula 1l −6.733 −4.112 2.621 Chemical Formula 1m −5.132 −2.492 2.640Chemical Formula 1n −5.404 −2.940 2.464 Chemical Formula 1o −5.632−3.025 2.607 Chemical Formula 1p −5.644 −3.070 2.574

Referring to Table 2, the compounds represented by Chemical Formulas 1ato 1p are found to have a HOMO level of about 4.3 to about 7.0 eV and anenergy bandgap of about 1.9 to about 3.1 eV.

Manufacture of Organic Photoelectronic Device Example 1

ITO is sputtered on a glass substrate to form an about 100 nm-thickanode, and molybdenum oxide (MoOx) is deposited to form a 30 nm-thickcharge auxiliary layer thereon. Subsequently, the compound according toSynthesis Example 3 (an n-type semiconductor) and a compound representedby the following Chemical Formula 3a (a p-type semiconductor) in athickness ratio of 1:1 are co-deposited to form a 70 nm-thick activelayer on the molybdenum oxide (MoOx) thin layer. Subsequently, aluminum(Al) is sputtered on the active layer to form an 80 nm-thick cathode,manufacturing an organic photoelectronic device.

Example 2

An organic photoelectronic device is manufactured according to the samemethod as Example 1, except for using a compound represented by thefollowing Chemical Formula 4 (an n-type semiconductor) and the compoundaccording to Synthesis Example 4 (a p-type semiconductor) instead of thecompound according to Synthesis Example 3 (an n-type semiconductor) andthe compound represented by the above Chemical Formula 3a (a p-typesemiconductor).

Example 3

An organic photoelectronic device is manufactured according to the samemethod as Example 1, except for using the compound according toSynthesis Example 4 (an n-type semiconductor) and a compound representedby the following Chemical Formula 3a (a p-type semiconductor) instead ofthe compound according to Synthesis Example 3 (an n-type semiconductor)and the compound represented by the above Chemical Formula 3a (a p-typesemiconductor).

Example 4

An organic photoelectronic device is manufactured according to the samemethod as Example 1, except for using the compound according toSynthesis Example 4 (an n-type semiconductor) and a compound representedby the following Chemical Formula 2a (a p-type semiconductor) instead ofthe compound according to Synthesis Example 3 (an n-type semiconductor)and the compound represented by the above Chemical Formula 3a (a p-typesemiconductor).

Example 5

An organic photoelectronic device is manufactured according to the samemethod as Example 1, except for using the compound according toSynthesis Example 4 (an n-type semiconductor) and a compound representedby the following Chemical Formula 2b (a p-type semiconductor) instead ofthe compound according to Synthesis Example 3 (an n-type semiconductor)and the compound represented by the above Chemical Formula 3a (a p-typesemiconductor).

Example 6

An organic photoelectronic device is manufactured according to the samemethod as Example 1, except for using the compound according toSynthesis Example 4 (an n-type semiconductor) and a compound representedby the following Chemical Formula 2d (a p-type semiconductor) instead ofthe compound according to Synthesis Example 3 (an n-type semiconductor)and the compound represented by the above Chemical Formula 3a (a p-typesemiconductor).

Evaluation 4: External Quantum Efficiency (EQE)

External quantum efficiency (EQE) of the organic photoelectronic devicesaccording to Examples 1 to 6 is evaluated depending on a wavelength anda voltage.

The external quantum efficiency is measured by using an IPCE measurementsystem (McScience Co. Ltd., Korea). First of all, the IPCE measurementsystem is calibrated by using a Si photodiode (Hamamatsu Photonics K.K.,Japan) and mounted on the organic photoelectronic devices according toExamples 1 to 6, and their external quantum efficiency is measured in awavelength range of about 350 to 750 nm.

FIGS. 6 to 11 are graphs respectively showing the external quantumefficiency (EQE) of the organic photoelectronic devices according toExamples 1 to 6 depending on a wavelength and a voltage.

Referring to FIGS. 6 to 11, the organic photoelectronic devicesaccording to Examples 1 to 6 show satisfactory external quantumefficiency (EQE) in a green wavelength region of about 500 nm to 600 nm.

Evaluation 5: Thermal Stability

Thermal stability of the organic photoelectronic devices according toExamples 4 and 5 is evaluated.

The thermal stability is evaluated by measuring current density changeof the organic photoelectronic devices according to Examples 4 and 5after being allowed to stand at 120° C. for 30 minutes.

FIG. 12 is a graph showing current density change of the organicphotoelectronic device according to Example 4 from room temperature (21°C.) after being allowed to stand at 120° C. for 30 minutes, and FIG. 13is a graph showing current density change of the organic photoelectronicdevice according to Example 5 from room temperature (21° C.) after beingallowed to stand at 120° C. for 30 minutes.

Referring to FIGS. 12 and 13, the organic photoelectronic devicesaccording to Examples 4 and 5 show that a dark current decreases afterthe organic photoelectronic devices are allowed to stand at 120° C. for30 minutes, and thus, characteristics of the organic photoelectronicdevices are found to be stabilized. Accordingly, the organicphotoelectronic devices according to Examples 4 and 5 show relativelyhigh thermal stability without deteriorating performance when beingallowed to stand at a relatively high temperature.

While this disclosure has been described in connection with what ispresently considered to be practical example embodiments, it is to beunderstood that the present disclosure is not limited to the disclosedembodiments, but, on the contrary, is intended to cover variousmodifications and equivalent arrangements included within the spirit andscope of the appended claims.

What is claimed is:
 1. A compound represented by one of the followingChemical Formulae 1d to 1n:


2. A thin film comprising the compound of claim
 1. 3. The thin film ofclaim 2, wherein the thin film shows an absorbance curve having a fullwidth at half maximum (FWHM) of about 50 nm to about 150 nm.